Experiment: Air Mass: A Weighty Topic by Heather Brinson Bruce

Did you notice a great weight hanging over your shoulders today? Well, it was—literally! If you worked out at the gym, for instance, 22 tons of air were above your head . . . how in the world did you ever survive?

Have you ever wondered why you can feel the wind blow against your face? How can something as empty as air cause ferocious hurricanes or tornadoes that rip apart whole cities?

Blasts of wind are possible because air has weight, just like your shoes or chair or car. Air actually weighs a lot because there is so much of it. Think about it—air covers the entire earth, way above the mountains. All that air is constantly exerting weight on every one of us.

How much does air weigh? That is actually a very complicated question. Air, being a gas, moves around. Its concentration varies from day to day, with changing weather and different altitudes (it weighs more on the beach than on top of a mountain). But if we assume it’s a pretty day and we’re standing on the beach, an average adult male is constantly subjected to a force of nearly 22 tons—just from the weight of the air!

The result of all this air is air pressure.

With so much air, why aren’t we crushed under its weight? When God designed us, He made sure our bodies were equipped to resist the effects of all that air. For instance, when we breathe, the air inside our lungs has roughly the same pressure as the air outside our lungs.

This balance keeps our bodies from crumpling under the weight of all the surrounding air. The balance of pressures explains why we can pick up objects like a flat screen television, despite all the air pushing down on it. The television does have tons of air pushing down against it, but it also has the same air pressure pushing against all its sides evenly. The air pushing up cancels out the air pushing down, leaving only the weight of the television itself for us to carry.

The weight of air benefits us in all sorts of ways in our day-to-day lives. Our bodies were designed not only to withstand air pressure but also to depend upon it for survival.

What would happen if your body were placed in the natural vacuum of outer space? Several terrible things would happen within minutes. First, the air in your lungs and blood would expand to take up the empty space.

Secondly, water boils at a lower temperature if there is no air pressure. In outer space, there is no pressure forcing the water molecules to stay together. This means that water becomes steam without changing the temperature! So all the water in your body would begin to boil. In fact, water can boil spontaneously in a vacuum, no matter what the temperature is.

Based on experiments on dogs during the Space Race of the 1960s, it is estimated that people can survive up to 90 seconds in the vacuum of space without suffering any permanent injuries, but not much longer. God, in His infinite wisdom, devoted one day of His Creation Week to create a perfect atmosphere with perfect air pressure for us to enjoy life with Him.

See For Yourself . . .

Do you need proof that air has weight? Try this simple experiment and see for yourself how much air can weigh.

 

Materials

1 clothes hanger
2 balloons (both the same size)
2 clothes pins

Procedure

• Find a place to hang the clothes hanger where it can swing freely.
• Clip one clothes pin to each end of the hanger, checking to ensure that the hanger balances evenly.
• Blow up one of the balloons and tie it closed.
• Clip each of the balloons (one inflated, one empty) to opposite ends of the hanger. Is the hanger still evenly balanced? Why is one end heavier than the other?